Chemistry Reference
In-Depth Information
For the phase transfer 5.00
g (1.66
mmol) of the K
7
[BW
11
O
39
Cu(H
2
O)] were dissolved in
120 ml of warm water (T = 55 °C) and a solution of 5.54 g(11.29 mmol; 6.8 eq.) Q
7
-Br in
100 ml toluene added. The organic layer was separated, the solvent removed under
reduced pressure and the green highly viscous product dried under vacuum for 24 h
with several times lyophilizing.
Yield (Q
7
)
7
[BW
11
O
39
Cu(H
2
O)]:
7.31 g (1.30 mmol, 78% based on K
7
[BW
11
O
39
Cu(H
2
O)])
EA
in wt. - % (calculated values in brackets): C 43.69 (41.93), H 7.95 (7.58), N 1.79 (1.75)
UV-Vis
spectrum:
0.4
0.3
699 nm
0.2
840 nm
0.1
0.0
400
600
800
1000
Wavelength
O
(nm)
Figure 60
UV-Vis spectrum of (Q
7
)
7
[BW
11
O
39
Cu(H
2
O)] in toluene (c = 19.3 mM). The extinction coefficients
are
H
699
= 12 M
-1
cm and
H
840
= 10 M
-1
cm.
IR
(characteristic bands in cm
-1
): 3568 (m), 2992/2955/2924/2870/2851 (s), 1638 (m),
1466 (m), 1456 (m), 1377 (m), 1082 (w), 1032 (w), 986 (m), 937 (m), 908 (m), 881 (m),
816 (m), 791 (m), 738 (w), 721 (m),
The (Q
7
)
6
[BW
11
O
39
Fe(H
2
O)] was synthesized in a similar fashion. At first
Na
6
[BW
11
O
39
Fe(H
2
O)] was synthesized as followed: 18.15 g (0.055 mol) Na
2
WO
4
ڄ
2H
2
O
were dissolved in 200
ml H
2
O and the solutions pH adjusted to 7.0 with HCl (4M). After
heating to 80
ι
C 2.75
g (0.044
mol) of H
3
BO
3
were added as solid. The reaction was
stirred for 15
min at this temperature and then added to a solution of 2.04
g (0.005
mol)
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